Introduction
Learning Objectives
- identify functions and categories of verbs
- identify helping verbs
- identify verb tenses
- identify subject and verb agreement
- identify verb tense consistency
- identify gerunds
- identify participles
- identify infinitives
From 2002 to 2006, The Centers for Disease Control (CDC) ran a media campaign entitled “Verb: It’s What You Do.” This campaign was designed to help teens get and stay active, but it also provided a helpful soundbite for defining verbs: “It’s what you do.”
Verbs are often called the “action” words of language. As we discuss verbs, we will learn that this isn’t always the case, but it is a helpful phrase to remember just what verbs are.
Traditionally, verbs are divided into three groups: active verbs (these are “action” words), linking verbs, and helping verbs (these two types of verbs are not “action” words). In this outcome, we’ll discuss all three of these groups. We’ll also learn how verbs work and how they change to suit the needs of a speaker or writer.
Active Verbs
Active verbs are the simplest type of verb: they simply express some sort of action. Watch this video introduction to verbs:
Let’s look at the example verbs from the video one more time:
- contain
- roars
- runs
- sleeps
All of these verbs are active verbs: they all express an action.
Practice
Identify the active verbs in the following sentences:
- Dominic paints the best pictures of meerkats.
- Sean’s hair curled really well today.
- Elephants roam the savanna.
- Billy ate an entire loaf of bread in one sitting.
Transitive and Intransitive Verbs
Active verbs can be divided into two categories: transitive and intransitive verbs. A transitive verb is a verb that requires one or more objects. This contrasts with intransitive verbs, which do not have objects.
It might be helpful to think of it this way: transitive verbs have to be done to something or someone in the sentence. Intransitive verbs only have to be done by someone.
Let’s look at a few examples of transitive verbs:
- We are going to need a bigger boat.
- The object in this sentence is the phrase “a bigger boat.” Consider how incomplete the thought would be if the sentence only said “We are going to need.” Despite having a subject and a verb, the sentence is meaningless without the object phrase.
- She hates filling out forms.
- Again, leaving out the object would cripple the meaning of the sentence. We have to know that “forms” is what she hates filling out.
- Sean hugged his brother David.
- You can see the pattern. . . . “Hugged” in this sentence is only useful if we know who Sean squeezed. David is the object of the transitive verb.
Intransitive verbs, on the other do not take an object.
- John sneezed loudly.
- Even though there’s another word after sneezed, the full meaning of the sentence is available with just the subject John and the verb sneezed: “John sneezed.” Therefore, sneezed is an intransitive verb. It doesn’t have to be done to something or someone.
- My computer completely died.
- Again, died here is enough for the sentence to make sense. We know that the computer (the subject) is what died.
This video provides a more in-depth explanation of transitive and intransitive verbs and how they work:
Note: there are some verbs that can act as both transitive and intransitive verbs (the video defined these as bitransitive verbs):
Intransitive | Transitive |
---|---|
The fire has burned for hundreds of years. | Miranda burned all of her old school papers. |
Don’t let the engine stop running! | Karl ran the best horse track this side of the river. |
The vase broke. | She broke the toothpick. |
Does your dog bite? | The cat bit him. |
Water evaporates when it’s hot. | Heat evaporates water. |
Practice
Read the following sentences. Are the verbs in each transitive or intransitive?
- Liv fell out of the car.
- Ian has written over four hundred articles on the subject.
- Christopher sings really well.
- Marton wondered about a lot of things.
- Cate gave great gifts.
Linking Verbs
A linking verb is a verb that links a subject to the rest of the sentence. There isn’t any “real” action happening in the sentence. Sentences with linking verbs become similar to math equations. The verb acts as an equal sign between the items it links.
As the video establishes, to be verbs are the most common linking verbs (is, was, were, etc.). David and the bear establish that there are other linking verbs as well. Here are some illustrations of other common linking verbs:
- Over the past five days, Charles has become a new man.
- It’s easy to reimagine this sentence as “Over the past five days, Charles = a new man.”
- Since the oil spill, the beach has smelled bad.
- Similarly, one could also read this as “Since the oil spill, the beach = smelled bad.”
- That word processing program seems adequate for our needs.
- Here, the linking verb is slightly more nuanced than an equals sign, though the sentence construction overall is similar. (This is why we write in words, rather than math symbols, after all!)
- This calculus problem looks difficult.
- With every step Jake took, he could feel the weight on his shoulders growing.
Practice
Read each sentence and determine whether its verb is a linking verb or not:
- Terry smelled his yogurt to see if it was still good.
- Rosa looks intimidating.
- Amy looked over at the clock to check the time.
- Gina smelled like chrysanthemums and mystery.
- Raymond is a fantastic boss.
Helping Verbs
Helping verbs (sometimes called auxiliary verbs) are, as the name suggests, verbs that help another verb. They provide support and add additional meaning. Here are some examples of helping verbs in sentences:
- By 1967, about 500 U.S. citizens had received heart transplants.
- While received could function on its own as a complete thought here, the helping verb had emphasizes the distance in time of the date in the opening phrase.
- Better immunosuppression management in transplant operations has yielded better results.
- This time, the helping verb adds clarity to the main verb yielded. Without it, the sentence would be difficult to understand.
- Researchers are finding that propranolol is effective in the treatment of heartbeat irregularities.
- The helping verb are adds immediacy to the verb finding.
Let’s look at some more examples to examine exactly what these verbs do. Take a look at the sentence “I have finished my dinner.” Here, the main verb is finish, and the helping verb have helps to express tense. Let’s look at two more examples:
- Do you want tea?
- Do is a helping verb accompanying the main verb want, used here to form a question.
- He has given his all.
- Has is a helping verb used in expressing the tense of given.
A list of verbs that (can) function as helping verbs in English is as follows:
- be (and all its forms)
- can, could
- dare
- do (and all its forms)
- have (and all its forms)
- may, might, must
- need
- ought
- shall, should
- will, would
The negative forms of these words (can’t, don’t, won’t, etc.) are also helping verbs.
Practice
Identify the helping verbs in the sentences below:
- Do you want Tim’s shift tonight?
- Cassandra couldn’t afford to give up.
- Richard was exercising when Barbara finally found him.
The following table shows examples of the helping verbs in standard English. Some helping verbs have more than one example as they can be used in multiple ways.
Helping Verb | Examples |
---|---|
be | He is sleeping. They were seen. |
can | I can swim. Such things can help. |
could | I could swim. That could help. |
dare | How dare you! |
do | You did not understand. |
have | They have understood. |
may | May I stay? That may take place. |
might | We might give it a try. |
must | You must not mock me. It must have rained. |
need | You need not water the grass. |
ought | You ought to play well. |
shall | You shall not pass. |
should | You should listen. That should help. |
will | We will eat pie. The sun will rise tomorrow at 6:03. He will make that mistake every time. |
would | Nothing would accomplish that. After 1990, we would do that again. Back then we would always go there |
Verb Tenses
What is tense? There are three standard tenses in English: past, present and future. All three of these tenses have simple and more complex forms. For now we’ll just focus on the simple present (things happening now), the simple past (things that happened before), and the simple future (things that will happen later).
Tenses
Present Tense
Watch this quick introduction to the present tense:
Past Tense
Watch this quick introduction to the past tense:
Future Tense
Watch this quick introduction to the future tense:
Other Forms of the Past, Present, and Future
You may have noticed that in the present tense video David talked about “things that are happening right now” and that he mentioned there were other ways to create the past and future tense. We won’t discuss these tenses in too much depth, but it’s important to recognize them.
We already discussed these briefly in Text: Helping Verbs. These forms are created with different forms of to be and to have:
- He had eaten everything by the time we got there.
- She is waiting for us to get there!
- He will have broken it by next Thursday, you can be sure.
- She was singing for eight hours.
When you combine to be with the –ing form of a verb you create a sense of continuity. The subject of the sentence was (or is, or will be) doing that thing for awhile. When you combine to have with the past participle of a verb, you create a sense of completion. This thing had been done for a while (or has been, or will have been). The sense of past, present, or future comes from the conjugation of to be or to have. For further discussion on this topic, look at the “Participles” section in Text: Non-Finite Verbs.
Conjugation
Most verbs will follow the pattern that we just learned in the previous videos:
Person | Past | Present | Future |
I | verb + ed | verb | will verb |
We | verb + ed | verb | will verb |
You | verb + ed | verb | will verb |
He, She, It | verb + ed | verb + s (or es) | will verb |
They | verb + ed | verb | will verb |
To Walk
Let’s look at the verb to walk for an example:
Person | Past | Present | Future |
I | walked | walk | will walk |
We | walked | walk | will walk |
You | walked | walk | will walk |
He, She, It | walked | walks | will walk |
They | walked | walk | will walk |
Practice
Change the tense of each sentence as directed below. You can type your answers in the text field below:
- Make this sentence present tense: Alejandra directed a play.
- Make this sentence past tense: Lena will show me how to use a microscope.
- Make this sentence future tense: Gabrielly eats a lot of hamburgers.
Irregular Verbs
There are a lot of irregular verbs. Unfortunately, there’s a lot of memorization involved in keeping them straight. This video shows a few of the irregular verbs you’ll have to use the most often (to be, to have, to do, and to say):
Subject & Verb Agreement
The basic idea behind sentence agreement is pretty simple: all the parts of your sentence should match (or agree). Verbs need to agree with their subjects in number (singular or plural) and in person (first, second, or third). In order to check agreement, you simply need to find the verb and ask who or what is doing the action of that verb.
Person
Agreement based on grammatical person (first, second, or third person) is found mostly between verb and subject. For example, you can say “I am” or “he is,” but not “I is” or “he am.” This is because the grammar of the language requires that the verb and its subject agree in person. The pronouns I and he are first and third person respectively, as are the verb forms am and is. The verb form must be selected so that it has the same person as the subject.
Number
Agreement based on grammatical number can occur between verb and subject, as in the case of grammatical person discussed above. In fact the two categories are often conflated within verb conjugation patterns: there are specific verb forms for first person singular, second person plural and so on. Some examples:
- I really am (1st pers. singular) vs. We really are (1st pers. plural)
- The boy sings (3rd pers. singular) vs. The boys sing (3rd pers. plural)
More Examples
Compound subjects are plural, and their verbs should agree. Look at the following sentence for an example:
A pencil, a backpack, and a notebook were issued to each student.
Verbs will never agree with nouns that are in prepositional phrases. To make verbs agree with their subjects, follow this example:
The direction of the three plays is the topic of my talk.
The subject of “my talk” is direction, not plays, so the verb should be singular.
In the English language, verbs usually follow subjects. But when this order is reversed, the writer must make the verb agree with the subject, not with a noun that happens to precede it. For example:
Beside the house stand sheds filled with tools.
The subject is sheds; it is plural, so the verb must be stand.
Agreement
All regular verbs (and nearly all irregular ones) in English agree in the third-person singular of the present indicative by adding a suffix of either -s or -es.
Look at the present tense of to love, for example:
Person | Number | |
---|---|---|
Singular | Plural | |
First | I love | we love |
Second | you love | you love |
Third | he/she/it loves | they love |
The highly irregular verb to be is the only verb with more agreement than this in the present tense:
Person | Number | |
---|---|---|
Singular | Plural | |
First | I am | we are |
Second | you are | you are |
Third | he/she/it is | they are |
Here’s a list of several irregular past tense verbs.
Practice
Choose the correct verb to make the sentences agree:
- Ann (walk / walks) really slowly.
- You (is / am / are) dating Tom?
- Donna and April (get / gets) along well.
- Chris and Ben (is / am / are) the best duo this company has ever seen.
Verb Tense Consistency
One of the most common mistakes in writing is a lack of tense consistency. Writers often start a sentence in one tense but ended up in another. Look back at that sentence. Do you see the error? The first verb start is in the present tense, but ended is in the past tense. The correct version of the sentence would be “Writers often start a sentence in one tense but end up in another.”
These mistakes often occur when writers change their minds halfway through writing the sentence, or when they come back and make changes but only end up changing half the sentence. It is very important to maintain a consistent tense, not just in a sentence but across paragraphs and pages. Decide if something happened, is happening, or will happen and then stick with that choice.
Read through the following paragraphs. Can you spot the errors in tense?
If you want to pick up a new outdoor activity, hiking is a great option to consider. It’s a sport that is suited for a beginner or an expert—it just depended on the difficulty hikes you choose. However, even the earliest beginners can complete difficult hikes if they pace themselves and were physically fit.
Not only is hiking an easy activity to pick up, it also will have some great payoffs. As you walked through canyons and climbed up mountains, you can see things that you wouldn’t otherwise. The views are breathtaking, and you will get a great opportunity to meditate on the world and your role in it. The summit of a mountain is unlike any other place in the world.
What errors did you spot? Let’s take another look at this passage. This time, the tense-shifted verbs have been bolded, and the phrases they belong to have been underlined:
If you want to pick up a new outdoor activity, hiking is a great option to consider. It’s a sport that is suited for a beginner or an expert—it just depended on the difficulty hikes you choose. However, even the earliest beginners can complete difficult hikes if they pace themselves and were physically fit.
Not only is hiking an easy activity to pick up, it also will have some great payoffs. As you walked through canyons and climbed up mountains, you can see things that you wouldn’t otherwise. The views are breathtaking, and you will get a great opportunity to meditate on the world and your role in it. The summit of a mountain is unlike any other place in the world.
As we mentioned earlier, you want to make sure your whole passage is consistent in its tense. You may have noticed that the most of the verbs in this passage are in present tense—this is especially apparent if you ignore those verbs that have been bolded. Now that we’ve established that this passage should be in the present tense, let’s address each of the underlined segments:
- It’s a sport that is suited for a beginner or an expert—it just depended on the difficulty hikes you choose.
- depended should be the same tense as is; it just depends on the difficulty
- if they pace themselves and were physically fit.
- were should be the same tense as pace; if they pace themselves and are physically fit.
- Not only is hiking an easy activity to pick up, it also will have some great payoffs.
- will have should be the same tense as is; it also has some great pay offs
- As you walked through canyons and climbed up mountains
- walked and climbed are both past tense, but this doesn’t match the tense of the passage as a whole. They should both be changed to present tense: As you walk through canyons and climb up mountains.
- The views are breathtaking, and you will get a great opportunity to meditate on the world and your role in it.
- will get should be the same tense as are; you get a great opportunity
Here’s the corrected passage as a whole; all edited verbs have been bolded:
If you want to pick up a new outdoor activity, hiking is a great option to consider. It’s a sport that can be suited for a beginner or an expert—it just depends on the difficulty hikes you choose. However, even the earliest beginners can complete difficult hikes if they pace themselves and are physically fit.
Not only is hiking an easy activity to pick up, it also has some great payoffs. As you walk through canyons and climb up mountains, you can see things that you wouldn’t otherwise. The views are breathtaking, and you get a great opportunity to meditate on the world and your role in it. The summit of a mountain is unlike any other place in the world.
Practice
Read the following sentences and identify any errors in verb tense:
- Whenever you go to the store, you should have made a list and stick to it.
- This experiment turned out to be much more complicated than I thought it would be. I ended up with a procedure that was seventeen steps long, instead of the original eight that I planned.
- I applied to some of the most prestigious medical schools. I hope the essays I write get me in!
Non-Finite Verbs
Just when we thought we had verbs figured out, we’re brought face-to-face with a new animal: the non-finite verbs. These words look similar to verbs we’ve already been talking about, but they act quite different than those other verbs.
By definition, a non-finite verb cannot serve as the root of an independent clause. In practical terms, this means that they don’t serve as the action of a sentence. They also don’t have a tense. While the sentence around them may be past, present, or future tense, the non-finite verbs themselves are neutral. There are three types of non-finite verbs: gerunds, participles, and infinitives.
Gerunds
Gerunds all end in -ing: skiing, reading, dancing, singing, etc. Gerunds act like nouns and can serve as subjects or objects of sentences. Let’s take a look at a few examples:
The following sentences illustrate some uses of gerunds:
- Swimming is fun.
- Here, the subject is swimming, the gerund.
- The verb is the linking verb is.
- I like swimming.
- This time, the subject of this sentence is the pronoun I.
- The verb is like.
- The gerund swimming becomes the direct object.
- I never gave swimming all that much effort.
- Do you fancy going out?
- After being elected president, he moved with his family to the capital.
Gerunds can be created using helping verbs as well:
- Being deceived can make someone feel angry.
- Having read the book once before makes me more prepared.
Often the “doer” of the gerund is clearly signaled:
- We enjoyed singing yesterday (we ourselves sang)
- The cat responded by licking the cream (the cat licked the cream)
- His heart is set on being awarded the prize (he hopes that he himself will be awarded the prize)
- Tomás likes eating apricots (Tomás himself eats apricots)
However, sometimes the “doer” must be overtly specified, typically in a position immediately before the non-finite verb:
- We enjoyed their singing.
- We were delighted at Bianca being awarded the prize.
Practice
Identify the gerunds and their roles in the following sentences:
- Sam was really bad at gardening.
- Studying is one of Jazz’s favorite things to do.
- Danny just wanted to go skateboarding.
Participles
A participle is a form of a verb that is used in a sentence to modify a noun, noun phrase, verb, or verb phrase, and then plays a role similar to an adjective or adverb. It is one of the types of nonfinite verb forms.
The two types of participle in English are traditionally called the present participle (forms such as writing, singing and raising) and the past participle (forms such as written, sung and raised).
The Present Participle
Even though they look exactly the same, gerunds and present participles do different things. As we just learned, the gerund acts as a noun: e.g., “I like sleeping“; “Sleeping is not allowed.” Present participles, on the other hand, act similarly to an adjective or adverb: e.g., “The sleeping girl over there is my sister”; “Breathing heavily, she finished the race in first place.”
The present participle, or participial phrases (clauses) formed from it, are used as follows:
- as an adjective phrase modifying a noun phrase: The man sitting over there is my uncle.
- adverbially, the subject being understood to be the same as that of the main clause: Looking at the plans, I gradually came to see where the problem lay. He shot the man, killing him.
- more generally as a clause or sentence modifier: Broadly speaking, the project was successful.
The present participle can also be used with the helping verb to be to form a type of present tense: Jim was sleeping. This is something we learned a little bit about in helping verbs and tense.
The Past Participle
Past participles often look very similar to the simple past tense of a verb: finished, danced, etc. However, some verbs have different forms. Reference lists will be your best help in finding the correct past participle. Here is one such list of participles. Here’s a short list of some of the most common irregular past participles you’ll use:
Verb | Simple Past | Past Participle |
---|---|---|
to be | was/were | been |
to become | became | become |
to begin | began | begun |
to come | came | come |
to do | did | done |
to drink | drank | drunk |
to eat | ate | eaten |
to get | got | gotten |
to give | gave | given |
to go | went | gone |
to know | knew | know |
to run | ran | run |
to see | saw | seen |
to show | showed | shown |
to speak | spoke | spoken |
to take | took | taken |
to throw | threw | thrown |
to write | wrote | written |
Past participles are used in a couple of different ways:
- as an adjective phrase: The chicken eaten by the children was contaminated.
- adverbially: Seen from this perspective, the problem presents no easy solution.
- in a nominative absolute construction, with a subject: The task finished, we returned home.
The past participle can also be used with the helping verb to have to form a type of past tense: The chicken has eaten. This is something we learned about in helping verbs and tense.
Practice
Identify the participles in the following sentences, as well as the functions they perform:
- Tucker had always wanted a pet dog.
- Having been born in the 1990s, Amber often found herself surrounded by nostalgia.
- Rayssa was practicing her flute when everything suddenly went wrong.
Infinitives
To be or not to be, that is the question.
—Hamlet
The infinitive is the basic dictionary form of a verb, usually preceded by to (when it’s not, it’s called the bare infinitive, which we’ll discuss more later). Thus to go is an infinitive. There are several different uses of the infinitive. They can be used alongside verbs, as a noun phrase, as a modifier, or in a question.
With Other Verbs
The to-infinitive is used with other verbs (we’ll discuss exceptions when we talk about the bare infinitive):
- I aim to convince him of our plan’s ingenuity.
- You already know that he’ll fail to complete the task.
You can also use multiple infinitives in a single sentence: “Today, I plan to run three miles, to clean my room, and to update my budget.” All three of these infinitives follow the verb plan. Other verbs that often come before infinitives include want, convince, try, able, and like.
As a Noun Phrase
The infinitive can also be used to express an action in an abstract, general way: “To err is human”; “To know me is to love me.” No one in particular is completing these actions. In these sentences, the infinitives act as the subjects.
Infinitives can also serve as the object of a sentence. One common construction involves a dummy subject (it): “It was nice to meet you.”
As a Modifier
Infinitives can be used as an adjective (e.g., “A request to see someone” or “The man to save us”) or as an adverb (e.g., “Keen to get on,” “Nice to listen to,” or “In order to win“).
In Questions
Infinitives can be used in elliptical questions as well, as in “I don’t know where to go.”
Note: The infinitive is also the usual dictionary form or citation form of a verb. The form listed in dictionaries is the bare infinitive, although the to-infinitive is often used in referring to verbs or in defining other verbs: “The word amble means ‘to walk slowly'”; “How do we conjugate the verb to go?”
Certain helping verbs do not have infinitives, such will, can, and may.
Split Infinitives?
One of the biggest controversies among grammarians and style writers has been the appropriateness of separating the two words of the to-infinitive as in “to boldly go.” Despite what a lot of people have declared over the years, there is absolutely nothing wrong with this construction. It is 100 percent grammatically sound.
Practice
Identify the infinitives in the following sentences:
- Paulina is the girl to beat.
- It was really nice to hear from you again.
- It looks like Dash wants to fail.
The Bare Infinitive
As we mentioned previously, the infinitive can sometimes occur without the word to. The form without to is called the bare infinitive (the form with to is called the to-infinitive). In the following sentences both sit and to sit would each be considered an infinitive:
- I want to sit on the other chair.
- I can sit here all day.
Infinitives have a variety of uses in English. Certain contexts call for the to-infinitive form, and certain contexts call for the bare infinitive; they are not normally interchangeable, except in occasional instances like after the verb help, where either can be used.
As we mentioned earlier, some verbs require the bare infinitive instead of the to-infinitive:
- The helping verb do
- Does she dance?
- Zi doesn’t sing.
- Helping verbs that express tense, possibility, or ability like will, can, could, should, would, and might
- The bears will eat you if they catch you.
- Lucas and Gerardo might go to the dance.
- You should give it a try.
- Verbs of perception, permission, or causation, such as see, watch, hear, make, let, and have (after a direct object)
- Look at Caroline go!
- You can’t make me talk.
- It’s so hard to let someone else finish my work.
The bare infinitive can be used as the object in such sentences like “What you should do is make a list.” It can also be used after the word why to ask a question: “Why reveal it?”
The bare infinitive can be tricky, because it often looks exactly like the present tense of a verb. Look at the following sentences for an example:
- You lose things so often.
- You can lose things at the drop of a hat.
In both of these sentences, we have the word lose, but in the first sentence it’s a present tense verb, while in the second it’s a bare infinitive. So how can you tell which is which? The easiest way is to try changing the subject of the sentence and seeing if the verb should change:
- She loses things so often.
- She can lose things at the drop of a hat.
Practice
Identify the infinitives in the following sentences:
- What you should do is stop talking for a moment and listen.
- Oh, that must be Lebo at the door.
- Why walk when I could run?
Self-Check
Candela Citations
- Outcome: Verbs. Provided by: Lumen Learning. License: CC BY: Attribution
- Revision and Adaptation of Wikipedia content. Provided by: Lumen Learning. License: CC BY-SA: Attribution-ShareAlike
- Text: Verb Tenses. Provided by: Lumen Learning. License: CC BY: Attribution
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- Bouncing Girl. Authored by: OpenClipartVectors. Located at: https://pixabay.com/en/bouncing-jump-child-girl-159517/. License: CC0: No Rights Reserved
- Transitive verb. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Transitive_verb. License: CC BY-SA: Attribution-ShareAlike
- Introduction to Verbs. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/introduction-to-verbs-the-parts-of-speech-grammar. License: CC BY-SA: Attribution-ShareAlike
- Intransitive verb. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Intransitive_verb. License: CC BY-SA: Attribution-ShareAlike
- Image of kicking figure. Authored by: Samy Menai. Provided by: The Noun Project. Located at: https://thenounproject.com/search/?q=karate&i=380644. License: CC BY: Attribution
- Linking Verbs. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/linking-verbs-the-parts-of-speech-grammar. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
- Image of chain. Authored by: Martin Chapman Fromm. Provided by: The Noun Project. Located at: https://thenounproject.com/search/?q=link&i=15066. License: CC BY: Attribution
- Auxiliary verb. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Auxiliary_verb. License: CC BY-SA: Attribution-ShareAlike
- Basic Patterns and Elements of the Sentence. Authored by: David McMurrey. Located at: https://www.prismnet.com/~hcexres/textbook/twsent.html. License: CC BY: Attribution
- Image of helping figures. Authored by: BenPixels. Provided by: The Noun Project. Located at: https://thenounproject.com/search/?q=help&i=462225. License: CC BY: Attribution
- The present tense. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/present-tense-verbs-the-parts-of-speech. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
- The past tense. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/the-past-tense-verbs-the-parts-of-speech. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
- The future tense. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/the-future-tense-verbs-the-parts-of-speech. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
- Introduction to irregular verbs. Authored by: David Rheinstrom. Provided by: Khan Academy. Located at: https://www.khanacademy.org/humanities/grammar/partsofspeech/grammar-verbs/v/introduction-to-irregular-verbs-the-parts-of-speech-grammar. License: CC BY-NC-SA: Attribution-NonCommercial-ShareAlike
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- Agreement (linguistics). Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Agreement_(linguistics). License: CC BY-SA: Attribution-ShareAlike
- Image of speech bubbles. Authored by: Gregor Cresnar. Provided by: The Noun Project. Located at: https://thenounproject.com/search/?q=agreed&i=441045. License: CC BY: Attribution
- Nonfinite verb. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Nonfinite_verb. License: CC BY-SA: Attribution-ShareAlike
- Gerund. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Gerund. License: CC BY-SA: Attribution-ShareAlike
- Participle. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Participle. License: CC BY-SA: Attribution-ShareAlike
- Infinitive. Provided by: Wikipedia. Located at: https://en.wikipedia.org/wiki/Infinitive. License: CC BY-SA: Attribution-ShareAlike
- Transitive and Intransitive Verbs | Natural English Grammar. Authored by: LikeANativeSpeaker . Located at: https://youtu.be/CFdl1oC1vtQ. License: All Rights Reserved. License Terms: Standard YouTube License
- Hiker At The Mountain Top. Authored by: Jean Beaufort. Provided by: Public Domain Pictures. Located at: http://www.publicdomainpictures.net/view-image.php?image=171368&picture=hiker-at-the-mountain-top. License: Public Domain: No Known Copyright